In recent years, there is a strong desire for an increase in the size of television sets and display devices for displaying information. Representative examples of large-sized display devices are display devices in which self-light-emitting elements such as light-emitting diodes (LEDs) are arranged in a matrix array and projection-type display devices; however, these have disadvantages in terms of image quality. Therefore, a further increase in the size of direct-viewing type liquid crystal display devices (LCDs) and plasma display devices (PDPs), which are capable of displaying with a high image quality, is being desired.
Since a direct-viewing type liquid crystal display device or a plasma display device is basically formed on a glass substrate, its screen size depends on the substrate size. Currently, the largest of glass substrates (mother substrates) that are used for the production of liquid crystal display devices are those of the eighth generation (2200 mm×2400 mm), and liquid crystal display devices whose diagonal is about 100 inches are being produced by using these substrates. The substrates that are available for mass production will become more increased in size, however at a slow rate. It is difficult to immediately provide display devices with the larger areas that are required on the current market.
Therefore, as a method of realizing a large-screen display device, there has been a conventional attempt of realizing a make-believe large-screen display device by arraying a plurality of display devices (which may be referred to as tiling). However, the tiling technique induces a problem of visible joints between the plurality of display devices. This problem will be described by taking a liquid crystal display device for example.
Note that a liquid crystal display device mainly includes a liquid crystal display panel, a backlight device, circuits for supplying various electrical signals to the liquid crystal display device, and a power supply, as well as a housing in which to accommodate these. The liquid crystal display panel mainly includes a pair of glass substrates and a liquid crystal layer provided therebetween. On one of the pair of glass substrates, pixel electrodes are formed in a matrix shape, and TFTs, bus lines, a driving circuit for supplying signals to them, and the like are formed, for example. On the other glass substrate, a color filter layer and a counter electrode are provided. The liquid crystal display panel has a display region in which a plurality of pixels are arrayed, and a frame region surrounding it. In the frame region, a sealing portion for allowing the pair of substrates to oppose each other and also sealing and retaining the liquid crystal layer, an implementation of driving circuitry for driving the pixels, and the like are provided.
Thus, since the frame region not contributing to any displaying exists in a liquid crystal display panel, when a large screen is constructed by arraying a plurality of liquid crystal display panels, the image will have joints. This problem is not limited to liquid crystal display devices, but is shared among direct-viewing type display devices, e.g., PDPs, organic EL display devices, and electrophoresis display devices.
Patent Document 1 discloses a construction which includes an optical fiber face plate covering the entire display panel, and the light going out from a display region is guided to a non-display region by the optical fiber face plate, such that jointless displaying is performed.
Patent Document 2 discloses a construction in which an optical fiber face plate complex is provided on the entire display panel, and the light going out from a display region is guided to a non-display region by the optical fiber face plate, such that jointless displaying is performed.
Patent Document 3 discloses a construction including an optical compensation means over substantially the entire display panel, the optical compensation means being composed of a multitude of slanted thin films and a transparent material filled between the slanted thin films, such that jointless displaying is performed by allowing light which is emitted from a display region to be guided to a non-display region by the optical compensation means.